Vacuum switch



May 24, 19320 c. H. NORTH L 5 VACUUM SWITCH Filed May 10, 1927 A TTORNEYS.

Patented May 24, 1932 UNITED STATES GEABLES H. NORTH, OF SAN FRANCISCO, CALIFORNIA VACUUM SWITCH 7 Application filed Kay 10, 1927. Serial No. 190,169.

This invention relates to a vacuum switch, and particularly pertains to a switch adapted to actuate a warning light on an automobile.

At the present time it is common practicebile engine and so constructed as to automatically close when the throttle is suddenly .closed, thereby causing the st up light circuit to be completed. V

The present invention contemplates the provision of a switch housing within which all of the contacting parts of the switch are encased, and which housing is provided with a flexible diaphragm adapted to be influenced by predetermined ranges of suction whereby the switch will be closed during suchrange 0 operation.

The invention-is illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is a view in rear elevation showing the switch housing with which the present inso vention is concerned, and one manner of mounting it.

Fig. 2 is a view in transverse section through the switch housing, as seen on the line 22 of "Fig. 3, anddiscloses the switch construction.

Fig.- 3 is a view in transverse vertical section through the switch as seen on the line 33 of Fig. 1.

Fig. 4 is a view in diagram showing the automobile engine and stop light for the vehicle, and the switch controlling the same.

Referring more particularly to the drawings, 10 indicates a cylindrical housing having a flexible end wall 11 completely closing one end of the housing, and a suitable cover 12 closing and sealing the opposite end of the housing. Disposed within the housing is a web 13 formed by the bearing 14, through which a switch pin 15 of dielectric material may slide. One end of this pin normally rests against the flexible end 11 of the housing, and the opposite end rests against a spring switch finger 16. This switch finger is carried by the cap 12 of the housing, and is secured in position by a binding post 17 which extends through a perforation in one end of the switch finger 16, and then passes through a perforation in an insulating sheet 18 and the end 19 of the cap 12. A lock nut 2O holds thebinding post in position. The end of this post extends outwardly and receives a binding screw 21 by which a wire 22 of the electrical circuit is secured in position. with relation to the binding post. The opposite or free end of the switch finger 16 is pro vided with a small curved contact face 23, which may be brought into electrical contact with a binding post '24, which also passes through the insulating plate 18 and the end of-the cap 12. This binding post is provided with a lock nut 25 and a binding nut 26 be-' tween which a conductor 27 is held. A suction duct 28 is secured through the side wall .along a conductor 33. A suitable fastening member, such, for example, as the cross plate 34:, is secured to the back of the switch housing to permit it to be conveniently mounted upon the dashboard of the car, or any other 35 desired position on the automobile.

When operating an automobile it has been determined that when idling the suction created by the engine within its intake manifold 30 is approximately 19 inches of mercury.

7 It will be understood that when the eration of the engine is abruptly interrupte ,as, for

. example, when the car is slowed down n traflic, the suction will be increased. This has been determined as being between 21 and 22 inches of mercury. 'The present invention is designed so that when this increased suction takes place the flexible end 11 ofthe switch housing will be deflected and caused to become concaved so that its inwardly deflected portion will force the switch pin 15 against the spring switch finger 16 and cause this finger to flex until contact has been made between the contacting portion 23 of the finger andthe end of the binding post 14. Attention is directed to the fact that the contacting parts of the switch are all enclosed within the housing, and that the compartment within the housing is under a partial condition of vacuum at all times when the engine is running. This will tend to eliminate the possibility of arcing between the switch pomts, and also makes the device safe in connection with automobile work, due to p the fact that the contacting members are at all times enclosed and are not liable to cause any accidental ignition of gas. condition of excessive vacuum has been relieved the flexibleendllwill return to its After the greater pressure on the outside of the casing than on the inside thereof by a predetermined amount will bend said resilient contact member to contact with said second binding post, the resiliency of said resilient contact memberbeing sufiicient to cause it to assume a position out of contact with said second binding post and to move said pin when the differences in pressures outside and inside the casing are decreased below said predetermined amount.

CHARLES H. NORTH.

normal position and the switch will then disclosed a very simple switch construction .is provided which may be very cheaply e, and will eflectively operate to automatically make and, break the circuit of warning light in direct relation to the operation of an automobile engine.

- While I have shown the preferred form of my invention as now known to me, it will be understood that various changes might be made in the combination, construction and arrangement of parts by those skilled in the art without departing from the spirit of my invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

A vacuum switch of the character described comprising a housing, and a cover therefor at one end thereof. said housing and said resilient contact member whereby n. It will thus be seen that'by the means here 

